1. Field of the Invention
The present invention, in general, relates to apparatus used with irrigation pipe and, more particularly, to devices that function as valves to control the flow of water through such types of pipe.
Irrigation pipe consists of various lengths and diameters of pipe and pipe fittings, each of which are connected together in a myriad of possible ways in order to satisfy the particular irrigation requirements of the area in which they are being used. The most common materials used to fabricate irrigation pipe are PVC and aluminum, although other types of material are also used on occasion.
Certain common types of irrigation pipe and pipe fittings interconnect with each other by having one end of each pipe or pipe fitting slip into a corresponding bell shaped enlarged portion of the remaining end thereof and by having a gasket located therein. Other types of irrigation pipe and pipe fittings utilize clamping arrangements that secure each of the gated pipes or pipe fittings together.
One characteristic common with most types of irrigation pipe is to have openings that are located at spaced apart intervals along the length of each section of irrigation pipe. Such types of irrigation pipe are commonly referred to as "gated" irrigation pipe.
Each of the openings is referred to as a "gate", hence the reason for referring to it as "gated pipe". Each gate typically utilizes a sliding or pivoting means to proportionally control the opening size. Each gate opening is either closed or is opened to an extent that determines the amount of water that is desired to be released therefrom.
Gated irrigation pipe greatly conserves water by depositing it in smaller amounts and in closer proximity to where it is required than by general flood irrigation methods.
It is, however, necessary to diminish or even to interrupt the flow of water entirely that is passing through certain sections of pipe. Typically, "butterfly" or "gate" types of valves are inserted as an adjunct fitting between sections of gated pipe when the gated pipe is assembled together.
These types of valves are expensive, and consequently few are incorporated into gated pipe systems except where thought to be absolutely necessary. As such there are often many locations along each "run", a run being a plurality of sections of irrigation pipe connected together, that stand to benefit from the use of gated pipe valves but, due to their high cost, are presently denied any such benefit.
Furthermore butterfly and gate valves for use with irrigation pipe are, as hereinbefore mentioned, inserted between the sections of pipe and fittings during assembly of those components together. If, after use, it is determined that a particular valve is needed elsewhere, it is then necessary to disassemble virtually all of the sections of irrigation pipe and fittings that are located between the existing and the desire valve locations, move the valve, and to then reassemble all of the sections together again.
In lieu of having either a sufficient quantity of valves located where needed or of moving a lesser number of valves from place to place, the individual gates that are present on gated irrigation pipe are grouped together with each group having a certain number of gates therein. Each group of gates is periodically opened a proportional amount to allow for the desired quantity of water to flow therefrom while all other groups of gates are simultaneously closed.
The quantity of water that is available is usually the factor that determines the number of gates to be contained within each grouping as well as the proportion to which each individual gate is to be opened. Each grouping is more commonly referred to as a "set".
After one set has finished supplying the desired quantity of irrigation to a particular area, each of the individual gates of that set are closed and all of the gates of another set are opened in proportion to the quantity of water that is desired to flow therefrom. The process of opening and closing the individual gates of each set is repeated continually during the course of the growing season. Such a practice, although common, is time consuming and is therefore also expensive of its own right.
Having a sufficient quantity of valves located so as to separate one set from each other set allows for an irrigator to proportionally open each of the gates as desired, usually only one time during each growing season. Initially, all of the valves are opened and water is allowed to flow through the gated pipe. Water will flow to the end of all of the sections of irrigation pipe and will begin to flow out from the gates that are located towards the end of the gated pipe sections.
Water that is flowing into the gated pipe will eventually establish equilibrium with the water that is flowing out of the gates. This occurs when the flow of water entering into the gated pipe equals the quantity of water that is flowing out from the gates. Ideally a valve is located immediately upstream from the last gate that is releasing water, thereby forming the first of several sets.
After a time has passed and irrigation of the first downstream set has been accomplished the valve that is located immediately above that particular set is closed thereby repeating the process whereby water will now flow from a second set of gates located immediately upstream from the valve. There is no requirement to close the individual downstream gates as no significant quantity water is allowed to flow beyond the closed valve. This process is repeated, merely by closing valves to enable new sets, until all of the irrigation sets are accomplished.
To repeat the cycle all of the valves are opened and the irrigation cycle begins again with the most downstream set. The primary savings gained by having a plurality of valves separating each set from every other set is a savings of time by not having to proportionately open and close each gate repeatedly. But due to the high cost of valves and the difficulty of moving them from place to place as needed, most gated pipe systems suffer from a shortage of valves and therefore require the repeated opening and closing of many individual gates.
Accordingly there exists today a need for a valve for use with irrigation pipe that may be readily moved from one section of pipe to another without requiring the dismantling of irrigation pipe sections.
2. Description of Prior Art
Valves for irrigation pipe are known. Butterfly and gate types of valves are presently in common use with irrigation pipe systems. Inflatable bladder type valves are also known but are not hereinbefore known for insertion through gate openings that are present on gated irrigation pipe or through other openings formed in the perimeter along the length of irrigation pipe.
For example, U.S. Pat. No. 2,598,207 to E. G. Bailey et al., that issued May 27, 1952, describes a valving apparatus for regulating the flow of a fluid through a conduit having an expansive member clamped to the wall of the conduit.
White U.S. Pat. No. 2,989,282 that issued Jun. 20, 1961, describes a diaphragm type of irrigation valve.
U.S. Pat. No. 3,022,977 to Jones, that issued Feb. 27, 1992, describes a vacuum operated normally closed valve.
U.S. Pat. No. 3,320,750 to Haise et al., that issued May 23, 1967, describes a remote control irrigation system having an inflatable bag that is fixedly clamped in place within a conduit.
U.S. Pat. No. 3,556,139 to Moslovskaya et al., that issued Jan. 19, 1971, describes a shutoff valve for hydraulic systems with high temperature aggressive media for use mainly in atomic and other power plants.
U.S. Pat. No. 4,182,371 to Moore, that issued Jan. 8, 1980 describes an automated control device or valve having an expandable bladder which controls the flow of fluid through a supply line or stops the flow after a predetermined amount of liquid has passed through the valve.
U.S. Pat. No. 4,785,841 to Breckner, that issued Nov. 22, 1988, describes a self clearing bladder valve.
While the structural arrangements of the above described devices, at first appearance, have similarities with the present invention, they differ in material respects. These differences, which will be described in more detail hereinafter, are essential for the effective use of the invention and which admit of the advantages that are not available with the prior devices.